Molded product for light-sensitive material, moisture-proof container for light-sensitive material and light-sensitive material package

Abstract

A molded product for a light-sensitive material is made by a process including a step of breaking a waterproof paper for printing paper to give a mixture of cellulose fibers and a polyolefin resin. The waterproof paper is obtained by laminating a base paper produced for printing paper with the polyolefin resin. An additional thermoplastic resin is added to the mixture if necessary. The mixture is then molded so that the ratio by weight of the base-paper-derived cellulose fibers to the total of the polyolefin resin and the additional thermoplastic resin is in the range of 51:49 to 75:25. A moisture-proof container for a light-sensitive material is also produced from a container for a light-sensitive material and a moisture-proof lining layer that are molded so that the ratio by weight of base-paper-derived cellulose fibers to the total thermoplastic resins is in the range of 51:49 to 75:25.

What is claimed is:  
     
         1 . A molded product for a light-sensitive material made by a process comprising steps of: 
 breaking a waterproof paper for printing paper, the waterproof paper being obtained by laminating a base paper produced for printing paper with a polyolefin resin, to give a mixture of cellulose fibers and the polyolefin resin;    adding an additional thermoplastic resin to the mixture if necessary; and    molding so that the ratio by weight of the base-paper-derived cellulose fibers to the total of the polyolefin resin and the additional thermoplastic resin is in the range of 51:49 to 75:25.    
     
     
         2 . The molded product for a light-sensitive material according to  claim 1 , wherein the mixture alone is temporarily formed into pellets, and these pellets and the additional thermoplastic resin are kneaded and molded.  
     
     
         3 . The molded product for a light-sensitive material according to  claim 2 , wherein the weight-average fiber length of the cellulose fibers after breaking is in the range of 0.30 mm to 0.50 mm.  
     
     
         4 . The molded product for a light-sensitive material according to  claim 1 , wherein the waterproof paper for printing paper is made from hardwood bleached kraft pulp having a cellulose fiber weight-average fiber length before breaking in the range of 0.4 mm to 0.7 mm, and the waterproof paper for printing paper is broken by a refiner.  
     
     
         5 . The molded product for a light-sensitive material according to  claim 1 , wherein the base paper is a neutral paper that is made in a neutral region where the pH is in the range of 6.0 to 7.5.  
     
     
         6 . A light-sensitive material package comprising: 
 a molded product for a light-sensitive material according to  claim 1;  and    a light-sensitive material that is used with the molded product.    
     
     
         7 . The light-sensitive material package according to  claim 6 , wherein the mixture alone is temporarily formed into pellets, and these pellets and the additional thermoplastic resin are kneaded and molded.  
     
     
         8 . The light-sensitive material package according to  claim 7 , wherein the weight-average fiber length of the cellulose fibers after breaking is in the range of 0.30 mm to 0.50 mm.  
     
     
         9 . The light-sensitive material package according to  claim 8 , wherein the waterproof paper for printing paper is made from hardwood bleached kraft pulp having a cellulose fiber weight-average fiber length before breaking in the range of 0.4 mm to 0.7 mm, and the waterproof paper for printing paper is broken by a refiner.  
     
     
         10 . The light-sensitive material package according to  claim 6 , wherein the base paper is a neutral paper that is made in a neutral region where the pH is in the range of 6.0 to 7.5.  
     
     
         11 . A moisture-proof container for a light-sensitive material comprising: 
 a container for a light-sensitive material and a moisture-proof lining layer that are molded so that the ratio by weight of base-paper-derived cellulose fibers to the total thermoplastic resins is in the range of 51:49 to 75:25.    
     
     
         12 . The moisture-proof container for a light-sensitive material according to  claim 11 , wherein the thickness of the moisture-proof lining layer is in the range of 0.05 to 0.2 mm.  
     
     
         13 . The moisture-proof container for a light-sensitive material according to  claim 11 , wherein the lining layer is provided by a two-color molding method.  
     
     
         14 . The moisture-proof container for a light-sensitive material according to  claim 11 , wherein the lining layer is provided by an insert-molding method.  
     
     
         15 . A light-sensitive material package comprising: 
 a moisture-proof container for a light-sensitive material comprising a container for a light-sensitive material and a moisture-proof lining layer that are molded so that the ratio by weight of base-paper-derived cellulose fibers to the total thermoplastic resins is in the range of 51:49 to 75:25; and    a light-sensitive material that is housed in the container.    
     
     
         16 . The light-sensitive material package according to  claim 15 , wherein the thickness of the moisture-proof lining layer is in the range of 0.05 to 0.2 mm.  
     
     
         17 . The light-sensitive material package according to  claim 15 , wherein the lining layer is provided by a two-color molding method.  
     
     
         18 . The light-sensitive material package according to  claim 15 , wherein the lining layer is provided by an insert-molding method.